1. Field of the Invention
The present invention relates to an improved headlamp for a vehicle, which is of a type containing a discharge lamp.
2. Description of Related Art
A headlamp for a vehicle is known, for example, from Japanese Patent Publication No. 2542962 entitled "Headlamp for Vehicle." The technique, as shown in FIG. 1 of this patent publication, describes a headlamp 1 for a vehicle, which includes a lamp housing 2 in which an opening on a front surface side thereof is covered with a lens and a rear surface thereof has an opening. A discharge lamp 8 is disposed in the lamp housing 2, wherein a lighting circuit 27 for lighting the discharge lamp 8 is provided in the opening provided in the rear surface of the lamp housing 2. The discharge lamp 8 is required to be applied with a high voltage, so that a low voltage is converted into a high voltage by the lighting circuit 27.
On the other hand, manual work is sometimes required to be performed in a lamp housing for the exchange of a discharge lamp. In a headlamp of a type in which a lighting switch is omitted, such manual work must be performed with care taken not to touch a portion that is applied with a high voltage. In other words, a lighting circuit is not configured to be cut off whenever work is performed.